Guys: Starting with PhotoShop V5.0 there is a setup wizard to guide you through calibrating your Monitor in order to establish a color profile for it (very useful to ensure that what you see on your monitor is what comes out of your printer!). Setting the Gamma is one of the steps in doing that. Gamma is the white point setting for the monitor (analogous to the center adjustment triangle in the levels dialog box). If you play around with that setting on one of your pictures, you'll see the effect easily. The Macs have always had a seperate gamma setting device incuded with the operating system, but this is somewhat new to Windows users (unless you are in the desktop publishing industry). Hope this helps you out :o) -Jim